As a new report from a leading pro-abortion research organization released this week indicates that the abortion rate in the United States is at its lowest level since abortion was made a national right in 1973, pro-lifers warn that the report does not tell the whole story.

The new report from the pro-choice Guttmacher Institute this week found that the abortion rate dropped to 13.5 abortions per 1,000 women aged 15 to 44 in 2017, which the organization says is the “lowest rate recorded since abortion was legalized in 1973” through the high court ruling in Roe v. Wade.

The report is based on data provided by the Guttmacher Institute abortion provider census.

The report also states that the total number of abortions per year has fallen by 19 percent from 2011 to 2017, with 862,000 abortions being performed in 2017 compared to the 1,058,000 abortions in 2011.

Additionally, the report shows that the number of abortions per 100 pregnancies that end in either abortion or live birth fell by 13 percent, from 21.2 to 18.4.

Although laws passed by several states govern how late into the pregnancy an abortion may legally be performed, the report concludes that the decline in births and pregnancies overall is playing more of a role in the abortion rate decline than such state laws.

Guttmacher Institute tallied 32 states enacting 394 policy restrictions on abortion from 2011 to 2017, the majority of which are in effect.

However, the report stressed that “nearly every state had a lower abortion rate in 2017 than in 2011, regardless of whether it had restricted abortion access.”

“There are a number of potential explanations for this broad decline, some more plausible than others,” the report contends. “Still, abortion restrictions, particularly those imposing unnecessary, intentionally burdensome regulations on providers, played a role in shutting down abortion clinics in some states and thereby reducing access to abortion.”

The Guttmacher report suggests that one factor for the decline in pregnancies could be “contraceptive access and use." It notes that since 2011 contraception has become more accessible and most private health insurance plans are now required by Obamacare to cover contraception.

The report explains that there is evidence to suggest that the use of long-acting reversible contraceptive methods increased through at least 2014. The increase was most recognizable among women in their 20s.

“Another study suggests that the use of IUDs might have increased in the wake of the 2016 presidential election, spurred by fears that such methods could become more expensive to access in the future,” the report reads. “Notably, contraceptive use has driven the long-term decline in adolescent pregnancies and births, which continued through the 2011–2017 period.”

Pro-life advocates have welcomed the findings of declining abortion in the U.S., however, they suggest that the report itself is incomplete in its analysis.

Melanie Israel, a research associate in the DeVos Center for Religion and Civil Society at the conservative policy think tank Heritage Foundation, objected to the report’s analysis.

“Guttmacher’s analysis of the declining abortion rate takes great pains to de-emphasize, erroneously, the impact of state-level pro-life legislation. Instead, Guttmacher emphasizes possible factors such as Obamacare’s contraception mandate,” she wrote in an op-ed. “But do contraception mandates actually lower rates of unintended pregnancy and abortion? Not so fast.”

She pointed to a study by Michael New, an associate scholar at the pro-life research organization Charlotte Lozier Institute and a visiting associate professor at Catholic University. New’s study concludes that state-level contraceptive mandates “do not lower rates of unintended pregnancy or abortion.”

“Notably, the rate of unintended pregnancies has decreased over time, and of those pregnancies, more and more are being carried to term,” Israel argued.

Israel also stresses that although the Guttmacher report shows a decline in abortion, the U.S. government does not “adequately track abortion data.” Even though the Centers for Disease Control and Prevention puts out annual data on abortion, the data is often “incomplete” and years behind.

The CDC’s most recent report from last year covered data from 2015. “And because reporting is voluntary, some states — namely, states with radically permissive abortion laws, such as California and New York — do not submit any data to the CDC,” she wrote.

The Guttmacher Institute report notes that it could be possible that the decline in abortion may not be “as large as it appears” in its abortion provider census. The report states that there could have been an increase in “self-managed abortions happening outside of medical facilities.”

The report comes as there has been a rise in chemical abortions, also known as medical abortion or medication abortion, which is done by taking an abortion pill.

Guttmacher’s census would not be able to capture self-managed abortions, the report admits.

“The rise in so-called medication abortion should concern us all,” Chuck Donovan, president of the Charlotte Lozier Institute, said in a statement after the report’s release.

“[I]t reveals the abortion industry’s increasingly successful effort to cut the overhead costs of surgical abortion while still profiting off the destruction of unborn children and wounding of his or her mother, who is given dangerous abortion drugs and then sent off to pass the body of her aborted child in isolation.”

Donovan, who leads the research arm of one of the largest pro-life lobbying groups in the country, Susan B. Anthony List, claims that the abortion industry’s “migration to chemical self-abortion is deeply disturbing.”

“[I]t carries with it the possibility of increasing the overall abortion rate over time and also carries with it a higher rate of injury, about which women are often under-informed or deceived,” he added.

Donovan also contends that part of the reason for the abortion decline shown in the Guttmacher Institute report is that moms in the U.S. are “ increasingly choosing life for their children, as well as choosing to identify themselves with the pro-life cause and pro-life policies.”

“This includes the broad protections for women and children being enacted at the state level such as strengthened health and safety standards for abortion facilities, limits on public funding of abortion, parental involvement laws, and increased informed consent,” Donovan stated.

While the abortion rate from the Guttmacher Institute data declined nationally, the abortion rate increased in six states: Maryland, Georgia, Minnesota, Mississippi, New Jersey, and Wisconsin.